Modeling/editing in imperial units
I believe if you switched to imperial units and just use for example extruding for 1.5 it will be 1.5 feet or 1'6". To do ' or " signs while doing these operation you need to use "advanced mode" pressing = after choosing operation. Not sure if there are addons/better ways for using imperial units. Some info on advanced mode from similar question. Also you could check "Separate Units" on Scene tab under Units settings, so you can see units as separate, otherwise by default you could see 1.5' instead of 1'6" during/after operations which can be quite confusing.